New research: Blast injury predicts PTSD

VA San Diego study of 1,650 Marines sheds light on resiliency issue

Dr. Dewleen Baker, lead investigator for Marine Resiliency Study at La Jolla VA stands next to the startle room. The room is used to measure the startled response to a visual as well as audiotory response.
— Nelvin C. Cepeda

Dr. Dewleen Baker, lead investigator for Marine Resiliency Study at La Jolla VA stands next to the startle room. The room is used to measure the startled response to a visual as well as audiotory response.
— Nelvin C. Cepeda

“Individuals with TBI show a very high incidence of chronic pain. It’s not necessarily due to primary injuries that occurred during combat. There is something more going on,” she said.

That kind of pain interferes with treatment, Strigo said.

“It hampers a lot of the (mental) resources I needed for TBI rehabilitation. They are used up with the pain. It increases disability, and it makes patients suffer,” she said.

Researchers tested 36 young post-Sept. 11 veterans in San Diego. Half had brain injuries; half didn’t. Strigo applied five seconds of 117-degree heat to the forearm of each participant.

The MRI scans of the injured veterans showed changes in blood flow in response to pain. Their brainstems were working overtime to control the pain, but the subjects reported no relief.

This study is the first to do imaging of pain among blast-injury veterans. More work is needed before researchers can say what this means for treatment, said Strigo, who is designing the next project now.

“Our study showed that there is something going on. They are not just complaining and trying to get out of work,” Strigo said. “So maybe it destigmatizes.”

At the VA’s San Diego Center of Excellence for Stress and Mental Health in San Diego, one of three similar VA centers in the nation, researchers are also looking to the next study.

Over the next few years, researchers there are hoping to extend the resiliency study.

Right now, they are using a magnetoencephalographic scanner to take images of the brains of Marines to study the effects of blast injuries. The scanner gives a detailed look at tissue and the current generated by the nerves inside the brain.

Perfecting diagnoses of these “invisible” injuries is one of the big projects ahead for the San Diego VA researchers in the next two to three years, Baker said.

Another is developing better medicines and alternative treatments.

A common complaint among veterans with PTSD is that drugs are prescribed too freely and that side effects are unpleasant.

Baker said they are working on modeling these disorders in animals to help move better medicines into regular use.

“We don’t understand the physiology sufficiently to make some of the new medicines that we would wish to have that might have fewer side effects or have better efficacy,” Baker said. “Our center is actively doing that.”

Another project is developing techniques to help treat pain and PTSD without drugs.

Baker mentioned transcranial magnetic stimulation, when weak electric current and a magnetic field are used to stimulate nerves.

Another possibility is stimulation of the vagal nerve that leads to the brain. The process is now used to treat epilepsy and depression but it has prospects for anxiety disorder and migraines.